| Diagram | Fig. 14 — PRIMARY TRANSMISSION AND OIL PUMP DRIVE · ref 23 |
| Subsystem | engine bottom |
| Listed in parts books | 1974 |
Engine sprocket (28T)
A 28-tooth Triumph engine sprocket for the primary drive, cataloged for 1974.
This is a Triumph engine sprocket, 28 tooth, listed under part number 71-6890. It's the drive sprocket that sits on the end of the crankshaft/gearbox mainshaft feeding the primary chain, per the catalog placement under the primary transmission and oil pump drive figure. The tooth count is part of its identity as a specific gearing option within the primary drive.
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Our catalog record for this one only shows a single appearance, tied to 1974. If you're matching this against your bike's parts book, check the tooth count and any other sprockets already fitted before you buy, since primary drive gearing has to be matched front to rear for the chain to run correctly.
Call the shop if you want us to confirm fitment against your particular machine before you order — the record we have is brief and we'd rather get you the right sprocket the first time.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
Sorry if we got something wrong here. If you think this information isn't correct, .